Wooden Yellow Balau Deck – Kloof, Durban KZN

Here’s another wooden deck we built in Kloof, Durban which is similar to one we built in Hawaan Forest estate a few years ago. It has a fire pit with a U Shaped bench which double up as steps around it. These steps were designed so that they were wide enough to sit around the fire and with a riser that is not too steep to climb.

The substructure or frame was the normal H3 and H4 CCA Treated S5 pine we use. All our decks are built with an S5, H3 and H4 treated pine substructure. S5 refers to the grade of pine which is commonly called industrial grade. It is graded as such based on the number of knots per square metre. S5 is SABS industrial grade and has been passed by SABS to be used in construction. It doesn’t however make a very good deck board as there are too many knots which are not only unsightly but also they can become dislodged leaving a hole in the deck board. H3 and H4 CCA Treated refers to the hazard classification of the treatment as set out by The Wood Preservers Association of South Africa. Each H classification has a specific application and provided the correct H classified timber is used, the life span of the timber can be many more than 50 years.

The deck boards that went on top of the substructure were 19 x 68mm yellow balau deck boards. The other option for deck boards is 19 x 90mm yellow balau deck boards but they do carry a surcharge as they cost more per square metre than the 68mm wide boards.

There are two types of balau readily available in South Africa. Yellow balau and red balau. Yellow balau is more common and is superior to red balau. What we are seeing in South Africa nowadays which is called red balau is a lot more porous and softer and as such will absorb more water and rot more quickly. We only stock and use yellow balau.

This project in Kloof also included a pergola. What we have found to be most cost effective in pergolas is to use a 90 x 90 square balau post, 30 x 215 balau beam and 30 x 102 balau purlins or trusses at about 600 centres. This spec gives the pergola enough timber to be attractive and serve its purpose whilst still keeping costs down. With this particular job we also installed extra battens on top of the purlins. We used 30 x 40 balau for this purpose which again keeps costs down whilst still providing enough timber to keep it looking good and to do it’s job. Other options for battens on pergolas are to use a 30mm wide strip of balau with a 30mm or 60mm gap between. This provides more shade but of course comes with a higher price tag because more timber is being used.

The timber was sanded and sealed with an oil based sealer we use which doesn’t dry on the surface of the wood so it cannot peel and flake. Unlike other coatings which dry on the surface. These tend to peel and flake.

For a free no obligation quote on your wooden deck, pergola, balustrade and stairs requirements please contact us on 082 496 5444 or use the contact us form below.

Wooden Pool Deck Building in Summerveld, Durban

We built this wooden pool deck in Summerveld, Durban in July 2015. There were various challenges in this wooden pool deck build which tested our skills somewhat.

Firstly the ground in Summerveld is very rocky, in fact in some areas it is just one large rock, and when digging you are actually making a small hole in a large piece of rock. There were 21 holes in total on this wooden pool deck so digging was slow and costly.

From the pics you can also see that the edge rim of the pool is a rock feature so it is not level or flat and we had to try to get our deck height to a comfortable level for access from the rock rim of the pool on to the wooden pool deck. We also had to then try to conceal the gap between rock and deck as far as possible and as neatly as possible. In some areas it took a full deck board as a fascia and in other areas it was tapered down to a half width deck board.

We ran deck boards perpendicular to the pool to avoid having long thin slivers of deck board on the pool side. When we started out the deck was planned to be half the finished size. As it took shape it was decided to extend it to its final measurements which was a double-edged sword for us as we had to dig even more holes through the rock but it increased our surface area and therefore our earnings. So we put on our big boy pants and carried on. The ends result was that the deck now extends past the front of the house so that when you are standing on the front you can see all the way along the front of the house.

A pool pump cover was added, a full balustrade around the whole deck and we clad the open vertical gaps so that one cannot see below the deck.

In one of the pics above you can see how we have returned the balustrade at 90 degrees on the first corner. This is to give the long run of balustrade perpendicular to it more strength. Long straight runs of balustrade can often become quite “wobbly” and this corner gives it good strength.

We opened a gap in the existing post and rail fence and built stairs from the garden at house level to the pool with a hinged gate and latch. Because of the angle of the stairs, and to prevent digging too deep into the ground at the top of the stairs, we built a small landing.

A short free-standing balustrade was added along the electric fence to provide some protection from the electric fence when accessing the lower garden on the right hand side of the deck.

For a free no obligation quote on your wooden pool deck or other outdoor timber structures please call us on 082 496 5444 or use the contact us form below.

Balau vs CCA Treated Wooden Deck Durban

I often get asked about using balau as a substructure in a wooden deck. There are various pros and cons of using balau as a substructure in your wooden deck so I thought I would jot it down and in future I can direct clients here who want the ins and outs of using balau as a structure for your wooden deck.

Balau is a very good, hardy and durable wood to use in outdoor wooden decks and other outdoor projects. It contains toxins that limit insects eating it and it is high in resins and oils which naturally repels water and limits rot. All wood will eventually rot. It is just that some will rot quicker as they are less dense and less oily which means they will absorb water more easily, which remains in the wood, causing fungus to grow which breaks down the fibres in the wood and is commonly called rot. This is a simplified explanation but I think it delivers the message accurately. Water doesn’t cause rot. Fungus, as a result of water and sunlight, causes rot.

Balau therefore will rot and I have started documenting some pics of rotten joists that I have come across in my repair work of wooden decks. It may take 15 years for this rot to start but it will happen and when it does repair work can run into thousands if not a complete deck rebuild. Joists are often difficult to access whereas deck boards are not.

On the other hand a piece of wood that has been chemically treated to prevent, or limit rot, will last a lot longer and a pre determined life span can be calculated.

CCA Treatment is a process of pressure treating SA pine. A vacuum is created in a chamber that contains the pine and a solution of copper, chrome and arsenate is introduced which then takes up the void created by the vacuum sucking the solution into the cells. The copper prevents fungus growing which in turn prevents rot, the arsenate keeps the insects away and the chrome binds the two to the wood so that I doesn’t leach out.

Balau is too hard and dense to treat. Pine is a commercially grown timber in South Africa which is inexpensive and very suitable for treatment as it is soft and takes up the solution of CCA successfully. There are various different Hazard Classification or H classifications. Basically H2 is good for indoors (roof trusses etc.) H3 for outdoors exposed to the elements, H4 for in constant contact with wet soil. H5 for submersion in fresh water and H6 for submersion in salt water. A correctly treated piece of pine to H3 will, as per SAWPA guidelines, last in excess of 50 years which is pretty impressive in comparison to a piece of balau that comes with no fixed life expectancy. A poor quality piece of balau may start to fail within 5 years whereas a good quality piece may only start in 15 years. Most of the pics I have documented here are of decks that range in age from 8 years to 15 years. But generally speaking I have found some rot setting in all the decks of 15 years or older.

S5 (SABS Structural grade) Pine is considerably cheaper than balau structural timber. So from an economic point of view it makes sense to use pine in place of other woods wherever possible.

One might now ask why is pine not used on the surface of a deck? Why is balau preferred?

Balau is a very stable wood and therefore expands and contracts less than pine. It is about twice as dense, knot free and doesn’t twist and warp as easily. Pine is soft and with the sun beating on the deck it will tend to crack, twist and warp more easily. To use pine as a deck board one needs to use a 38mm board as opposed to a 19mm board in balau (twice as much wood). Also pine deck boards are normally manufactured from S7 as opposed to S5. S7 refers to the number of knots per square inch (or centimetre) and is therefore a lot more expensive than S5. The cost of pine deck boards is in fact a few rand more per square metre than balau. Hence the reason to use correctly treated CCA pine as a substructure and balau as deck boards. Again pine doesn’t work well in balustrades because twice as much wood needs to be used at S7 grade.

For a free no obligation quote on your sun deck, pool deck, balustrades, pergolas etc., please call us on 082 496 5444 or use the contact us form below.